Method of mounting disk sensing optics onto circuit board of watthour meter

ABSTRACT

A disk sensing optics assembly is mounted directly on the register circuit board of an electronic energy meter. The molded optics assembly includes an central cavity adatped to receive a discontinuous rotating shutter, and pockets on either side dimensioned to hold and position pairs of light emitters and detectors on opposite sides of the shutter to detect speed and direction of rotation of the shutter. Apertures through the rear of the housing are adapted to position and secure the electrical leads from the light emitters and detectors within the housing and are soldered to the register printed circuit board. Positioning means integral with the housing and register circit board space, position, and secure the disk sensing optics and the assembly to the register circuit board with the electrical leads properly positioned for soldering to the circuit board.

This is a divisional of copending application(s) Ser. No. 07/505,383filed on Apr. 5, 1990, now U.S. Pat. No. 5,034,682.

BACKGROUND OF INVENTION

The present invention relates to electric energy meters, and moreparticularly to a method and apparatus for mounting the disk sensingoptics on the register printed circuit board of a time of use electricenergy register.

The use of electronics in electric energy meters has enabled the designof energy meters with greatly increased capability and functions.However, there is increasing pressure for such meters to have fewerparts and to be substantially smaller than previous designs. Fewer partsare required in order to minimize manufacturing costs, including thecost of materials and assembly, and the subsequent cost and number ofcomponents which must be maintained for spare parts and repair purposes,along with an increase in reliability which accompanies designs whichhave fewer parts.

Induction watthour meters conventionally utilize the rotation of an eddycurrent disk in response to the power consumption on the lines beingmetered, which is then totalized or integrated as a measure of energyconsumption, usually in Kilowatt hours. In electronic registers for usein induction watthour meters, a series of electrical pulses is used toprovide an electrical signal responsive to the rate of energyconsumption. This is usually achieved by mounting a toothed opticalshutter on the eddy current disk shaft of the meter for rotation withthe shaft, and positioning a light source and detector on opposite sidesof the shutter. The toothed shutter interrupts the light path betweenthe light source and a light detector as it rotates between them at arate proportional to the rate of energy consumption by the load beingmetered. Two pairs of light emitters and detectors are typically used insuch arrangements in order to detect shutter rotation direction.Typically, the light emitting and detecting pairs are housed in anassembly separate from the register and interconnected to the registerby means of a cable. Directly mounting the disk sensing optics on theregister printed circuit board eliminates the need for a separatecircuit board and connecting cable, and in addition assists in reducingthe size of the electronic register along with a reduction in otherparts. However, the components of the disk sensing optics have to beaccurately located relative to each other and to the optical shutter,and in addition must be shielded from external or ambient light in anenergy meter including the usual transparent housing or case which maybe positioned in direct sunlight or other bright light. In addition, itis desired to obtain accurate positioning, and shielding, of the disksensing optics while at the same time avoiding any requirement forspecial fixturing during the manufacturing process.

OBJECTS AND SUMMARY OF INVENTION

It is an object of the present invention to minimize the components in,and size, of an electric energy meter.

It is another object of the present invention to mount the disk sensingoptics on the register circuit board of an electronic time of useregister, while at the same time avoiding the need for special fixturingduring the manufacturing process.

It is yet another object of the present invention to provide means foraccurately locating and shielding the disk sensing optics on theregister circuit board of an electronic energy meter.

Still another object of the present invention is to provide an improved,yet simple, method for accurately mounting the disk sensing optics onthe register printed circuit board of an electronic time of useregister.

It is a further object of the present invention to simplify the assemblyand maintenance of the disk sensing optics in an electronic time of useregister.

In accordance with one embodiment of the present invention the disksensing optics of an electronic time of use register in an electricenergy meter is mounted on the register printed circuit board in amolded plastic housing which serves to shield the optics from ambientlight and in addition accurately positions and holds the components ofthe disk sensing optics in place relative to the circuit board, and toeach other. The assembly is designed for simple mounting to the registerprinted circuit board without fixturing, while providing fastening meansto the printed circuit board once positioned.

More particularly, the assembly includes a molded housing defining acentral chamber in which a castellated shutter rotates between 2 pairsof light emitter and detectors positioned on opposite sides of theshutter in pockets which contain apertures to guide, position and holdthe light emitters and detectors. The housing further includespositioning and fastening members to position and fasten the housing tothe register circuit board in such a way that the leads from the lightemitters and detectors are positioned to extend through holes in thecircuit board for subsequent soldering. The cross section of the roundapertures in the housing is less than that across the corners of therectangular leads of the light emitters and detectors such that when theleads are forced through the apertures they cut, and are held by, theplastic housing. The positioning and fastening means in one embodimentincludes resilient jaws on one positioning member and spacers moldedintegral with the housing.

DRAWINGS AND BRIEF DESCRIPTION OF INVENTION

FIG. 1 is a side view of a watthour meter incorporating an electronictime of use register and incorporating one embodiment of the presentinvention.

FIG. 2 is a side view simplified diagram of the shutter optics utilizedin the present invention.

FIG. 3 is a top view, partially in cross section, of FIG. 2.

FIG. 4 illustrates the assembly and mounting of the optics in accordancewith one embodiment of the present invention.

FIG. 5 shows some of the details of the register assembly which isincluded within the power meter of FIG. 1.

FIG. 6 shows details of the assembly of the optical emitter anddetectors shown in FIGS. 3 and 4.

FIG. 7 is a perspective view of the rear of the housing shown in FIG. 6.

Referring first to FIG. 1, an electronic or electric energy meter 2 isshown in simplified form and includes a base 4 having a plurality ofcircuit terminals such as 8 and 10 extending through the base to connectthe meter in circuit with a power source and a load which is to bemetered. An electronic register assembly 20 is positioned remote fromthe base 4 and meter circuit terminals 8 and 10 and the internalelectronics and mechanism of the energy meter 2 is enclosed by atransparent cover or enclosure 22 which is secured to the base 4 by alocking ring 24. Optical shutter 28 is supported on a shaft 30 forrotation within bearings 32 and 34 in response to electric powersupplied to, and consumed by, a load which is to be metered in circuitwith the energy meter 2 and connected through circuit terminals such as8 and 10. In a manner well known in the art, the eddy current disk 27 iscaused to rotate at a speed proportional to the power provided to theload circuit to which the energy meter 2 is connected, and the watthourmeter integrates the revolutions of the eddy current disk as a measureof energy consumption.

As shown somewhat schematically by FIGS. 2 and 3, the optical shutter ordisk 28 also is mounted on, and rotates with, shaft 30 between spacedjaws 40 and 42 of the optical disk sensing optics assembly 44. As bestshown in FIG. 3, the optical shutter 28 is castellated and includes aplurality of radially extending teeth 46 which sequentially pass betweenthe spaced jaws 40 and 42. Positioned within the spaced jaws 40 and 42are 2 pairs of light emitters 84 and 86 and detectors 88 and 90 whichare in the path of the teeth 46 such that upon rotation of the shutter28 in the direction shown, for example, by arrow 48, the teeth willsequentially rotate first past one light emitter and detector pair 86,90 and then past the second light emitter and detector pair 84, 88.Thus, a light source or light emitter 84, 86 is positioned on theopposite side of the optical shutter 28 from the cooperating lightdetector 88, 90 respectively, such that the light transmissions from thelight sources to the light detectors are twice interrupted every time atooth 46 passes between the jaws 40 and 42.

The disk sensing optics assembly 44 of the present invention are securedto the register printed circuit board 62 which is located within theelectronic register assembly 20 of the energy meter 2 as best shown inFIGS. 1 and 5.

Details of the disk sensing optics assembly 44 are best shown by FIGS. 4and 7. Referring to FIGS. 4 and 7, the molded plastic housing 68includes the spaced jaws 40 and 42 which are positioned on either sideof the central cavity 70 through which the teeth 46 of the castellatedoptical shutter 28 rotate. Molded integral with the housing 68 are twopairs of rectangularly shaped pockets 74, 76, 78 and 80. The housing 68is molded from glass-filled nylon, with 6-33% glass to provide desiredstiffness. Rectangularly shaped pockets 74 and 76 are positioned side byside on one side of the central chamber 70 while a second pair ofrectangularly shaped pockets 78 and 80 are positioned side by side onthe opposite side of the central chamber. The rectangularly shapedpockets 74 and 78 are configured to receive, position and secure thepaired light emitter 84 and light detector 88 respectively, while therectangularly shaped pockets 76 and 80 are configured to receive,position and secure the paired light emitter 86 and light detector 90respectively. The interior surfaces of the rectangularly shaped pockets74, 76, 78 and 80 include centrally located radiation slots 94, 96, 98and 100 respectively, to enable passage of the light beams between thelight emitter-detector pairs 84, 88 and 86, 90. The light emitters 84and 86 and the light detectors 88 and 90 each include a pair ofelectrical leads or connectors 108 which are rectangular in crosssection and which extend in planes perpendicular to the axis of rotationof shaft 30. Four pairs of holes 113 in the molded housing 68 alsoextend from the ends of the rectangularly shaped pockets or cavities 74,76, 78 and 80 through the cylindrical posts or columns such as 112, 114,116 and 118, and 113, 115, 117 and 119 which extend outward from thecentral regions of the rectangularly shaped pockets or cavities. Theholes or apertures 113 are positioned to be aligned with the electricalleads or connectors 108, when the emitters 84 and 86 and detectors 88and 90 are slid into the rectangularly shaped pockets.

As best shown in FIG. 6, the holes 113 in the housing 68 are round incross section and slightly smaller than the cross section of the squareleads 108 of the emitters 84 and 86 and detectors 88 and 90. The leads108 are 0.020 inches square with a diagonal across alternate corners115, 115 and 119, 119 of approximately 0.028 inches. The holes 113 are0.026 inches in diameter with tapered or funnel shaped ends, orcountersunk holes, 117 adjacent pockets 74, 76, 78 and 80. When thelight emitters 84 and 86 and light detectors 89 and 90 are slid intoplace into the rectangularly shaped pockets 74, 76, 78 and 80 funnelends 117 assist in guiding the leads 108 into the apertures 113. Thisassistance may be required if the leads 108 have been bent or misalignedby handling or during insertion of light emitters 84 and 86 and lightdetectors 88 and 90 into the rectangularly shaped pockets 74, 76, 78 and80. Continued pressure on the light emitters and light detectors causethe corners 115 and 119 of leads 108 to cut into the plastic surroundingthe holes in the molded plastic housing 68. This grasps the leads 108and serves to hold the emitters 84 and 86 and detectors 88 and 90 inplace during the subsequent soldering operation.

The register printed circuit board 62 includes four pairs of holes 126,128, 130 and 132 which are 0.007-0.008 inch larger than the electricalleads 108 and are positioned for alignment with the electrical leads ofthe emitters 84 and 86 and detectors 88 and 90. The electrical leads 108are long enough so that they extend through holes 113 and beyond thecylindrical posts 112, 114, 116 and 118 when the light emitters 84 and86 and the light detectors 88 and 90 are fully positioned within therectangularly shaped pockets 74, 76, 78 and 80.

A pair of positioning and fastening posts 136 extend between the rows ofcylindrical posts such as 112, 114, 116 and 118 to mate with thepositioning apertures 138 and 140 in the register printed circuit board62 to guide the disk sensing optics assembly 44 accurately into positionwith the register printed circuit board. One or more resilient jaws 156on the ends of posts 136 are compressed inwardly for insertion and thensnap outward after passing through the register printed circuit board 62to secure the disk sensing optics assembly 44 in place on the registerprinted circuit board FIG. 7 shows the embodiment utilizing single jaws156 although a pair of spaced jaws on the ends of posts 136 have alsoproven effective. The jaws 156 are larger in cross section than theposts 136 so that after compression of the jaws inward and insertionthrough the apertures 138 and 140 the jaws snap outward to overlie aportion of the opposite side 154 of the register printed circuit board62.

In a preferred embodiment of the present invention, the housing 68 ofthe disk sensing optics assembly 44 is first positioned on the registerprinted circuit board 62 and the light emitters 84 and 86 and the lightdetectors 88 and 90 are then individually inserted and positioned withinthe rectangularly shaped pockets 74, 76, 78 and 80, respectively asdescribed above, with the electrical leads 108 being guided by thehousing 68 to extend the proper predetermined distance through the holes126, 128, 130 and 132 in the register printed circuit board. Holes 126,128, 130 and 132 are 0.007 to 0.008 larger than the electrical leads 108to provide space for good solder connections to the electrical runs orconductors on the register printed circuit board 62. In an alternateembodiment of the present invention, the light emitters 84 and 86 andthe light detectors 88 and 90 are inserted and positioned within therectangularly shaped pockets 74, 76, 78 and 80, respectively, before thedisk sensing optics assembly 44 is positioned on the register printedcircuit board 62. In this case, slightly stiffer and heavier electricalleads 108 are desirable, in the order of 0.025 inches square, and thediameter of holes 113 would also be increased, to 0.031 inches orslightly larger. The molded plastic housing 68 also includes a pluralityof spacers such as 146 and 148 which extend in planes radially to theaxis of rotation of shaft 30 and outward from the rear of the housingparallel to the central chamber 70, a larger distance than thecylindrical posts such as 112, 114, 116 and 118. As a result, when thedisk sensing optics assembly 44 is assembled to the register printedcircuit board 62 the spacers such as 146 and 148 help support andposition the housing relative to the register printed circuit board,while the cylindrical posts such as 112, 114 116 and 118 are spaced fromthe register printed circuit board 62 to facilitate cleaning after thesoldering operation.

Assembly of the disk sensing optics assembly and positioning on theregister printed circuit board 62 in preparation for soldering to theregister printed circuit board is thus accomplished simply andaccurately without any fixturing. In the preferred embodiment, the disksensing optics assembly 44 is brought into mating contact with theregister printed circuit board 62 by simply pushing the positioning andfastening posts 136 through the positioning apertures 138 and 142.Referring to FIGS. 4, 6, and 7, the resilient jaws 156 of thepositioning posts 136 are compressed together, or inwardly, as thepositioning posts are forced through the positioning apertures 138 and140 until they extend beyond the opposite surface 154 of the registerprinted circuit board 62. Providing a slightly larger diameter for theresilient jaws 156 at the outer ends of the positioning posts 136provides a snap action after the positioning posts extend through theregister printed circuit board 62, where the resilient jaws are free toexpand and surround the edges of apertures 138 and 140 on the oppositesurface 154 of the register printed circuit board. This properlypositions the disk sensing optics assembly 44 on the register circuitboard 62 and aligns the central holes 113 of the cylindrical posts112-118 with the mating holes 126, 128, 130 and 132 in the registerprinted circuit board 62. The emitters 84 and 86 are then slid intorectangularly shaped pockets 74 and 76, and detectors 88 and 90 are slidinto rectangularly shaped pockets 78 and 80. The rectangularly shapedpockets 74, 76, 78 and 80 guide the emitters and detectors 84, 86, 88and 90 to accurately position the electrical leads 108 into contact withthe holes 113 in the rear of the rectangularly shaped pockets 74, 76, 78and 80 such that pressure on the emitters and detectors with theguidance of the funnel ends 117 force the square leads through theslightly smaller round holes, cutting into the plastic surrounding theholes in the molded plastic housing 68. This simple procedure accuratelyand securely positions the emitters and detectors in the housing withthe ends of the electrical leads 108 extending beyond the cylindricalposts such as 112, 114, 116 and 118 and through the register printedcircuit board 62 holes 126, 128, 130 and 132 a distance controlled bythe spacers such as 146 and 148 contacting the adjacent surface 152 ofthe register printed circuit board. As a result, the electrical leads108 extend the proper short distance beyond the opposite surface 154 ofthe register printed circuit board for subsequent soldering.

The disk sensing optics assembly 44 and the various optical componentsof the assembly have thus been securely fastened to the register printedcircuit board 62 in a simple procedure which does not require anyspecial fixturing, which minimizes parts, and which reduces the laborinvolved in the assembly. The simple assembly procedure properly andaccurately positions light emitter 84 relative to light detector 88,light emitter 86 relative to light detector 90, and also relative to theoptical shutter 28. The disk sensing optics assembly 44 and leads 108have been properly positioned and may then be soldered in circuit withregister printed circuit board 62 to provide the electrical connectionsto the printed circuit board. The molded plastic housing 68 is alsorelieved by the spacers such as 146 and 148 near the printed circuitboard 62 to provide access to the electrical leads 108 entry area sothat solder flex residue may be easily removed. The soldering of theleads 108 to the register printed circuit board 62 may be accomplishedby flow soldering or other soldering means well known in the art. Theregister printed circuit board assembly is now ready to be installed inthe register assembly

The register assembly is best shown in FIG. 5. Referring to FIG. 5, theregister assembly 20 includes an enclosure 160 which is positionedwithin the energy meter 2 remote from the base 4 (see FIG. 1) andincludes a liquid crystal display 162, with an intermediate electronicassembly including the register printed circuit board 62 upon which ismounted the disk sensing optics assembly 44 and other electroniccomponents such as the high voltage power supply transformer 166. Theassembly and mounting of the high voltage power supply transformer 166is disclosed in copending United States patent application Ser. No.505,194, filed Apr. 5, 1990, now U.S. Pat. No. 5,087,875, in the name ofA. A. Keturakis, R. A. Balch, and S. D. Velte, assigned to the sameassignee as the present invention, and hereby incorporated by reference.The register printed circuit board 62 is mounted within the energy meter2 such that the open end of the central chamber 70 between jaws 40 and42 is positioned away from the liquid crystal display 162. The registerprinted circuit board 62 is thus interposed between the disk sensingoptics assembly 44 and the ambient light outside the transparent cover22 and optical readout or communications port 170 of the electronicenergy meter 2. The details of the optical communications port aredisclosed in copending United States patent application Ser. No.505,970, filed Apr. 5, 1990, now U.S. Pat. No. 5,057,767 in the name ofA. A. Keturakis and S. D. Velte, and the details of the mounting of theregister printed circuit board 62 in the register enclosure 160 inproper alignment with the optical shutter 28 are disclosed in copendingUnited States patent application Ser. No. 505,195, filed Apr. 5, 1990,now U.S. Pat. No. 5,027,056 of A. A. Keturakis, S. D. Velte, J. G.Russillo, Jr., and R. A. Balch, both of which patents are assigned tothe same assignee as the present invention, and are hereby incorporatedby reference.

Thus, the register disk sensing optics assembly 44 has been directlymounted on the register printed circuit board 62 without fixturing andis accurately assembled and positioned, including the positioning andassembly of the optical and electrical components within the energymeter 2 with a minimum of parts and a minimum of manufacturing time andcost. The assembly provides concurrent positioning of each of the lightemitters 84 and 86 relative to the corresponding light detectors 88 and90, and with the cooperation of funnel ends 117, positions and securesthe electrical leads 108 in the holes 113, and secures the lightemitters and light detectors within their respective pockets. Theassembly also properly positions for soldering the leads 108 in theholes 126, 128, 130 and 132 in the register printed circuit board 62through cooperation of the positioning and fastening posts 136 andapertures 138 and 142. In addition, the disk sensing optics assembly 44has been adequately shielded from the ambient light passing through thetransparent cover or enclosure 22 or through optical port 170 fromoutside the electronic energy meter. Still further, the assemblypositions central aperture 70 relative to optical shutter 28.

In another embodiment of the present invention the cylindrical postssuch as 112, 114, 116 and 118 (see FIG. 7) may be eliminated such thatthe leads 108 extend through the relief space provided by spacers suchas 146 and 148. Also, two spacers, rather than two pairs of spacers 146and 148, may be adequate, in which case they may conveniently be thespacers 146 placed on opposite ends of the molded plastic housing 68, asshown in FIG. 7. The radially extending grooves 180 and 182 (see FIG. 4)assist in the extraction and cooling of the molded plastic housing 68from the mold while still warm. After encountering problems, it wasdetermined that the mass of the walls in the regions between pockets 74and 76, and in the regions between pockets 78 and 80, resulting from thecooling of the molded plastic housing 68 after removal from the moldtends to cause a sag in the housing along the outer surface of thoseregions in the absence of grooves 180 and 182 which allow cooling withinthe walls between adjacent pocket pairs. The grooves 180 and 182 allow amore even final cooling of the walls from both within and outside,preventing the deleterious sagging of the central portion of the moldedhousing 68 in the regions between the pockets.

Thus, while the present invention has been described through preferredembodiments, such embodiments are provided by way of example only.Numerous variations, changes and substitutions, including thosediscussed above will occur to those skilled in the art without departingfrom the scope of the present invention in the following claims.

What we claim is:
 1. A method of positioning and mounting a disk sensingoptics assembly on the register circuit board of an electronic registerin an electric energy meter comprising the steps of:molding a housingincluding a central chamber open at one end, with one or more pocketspositioned on either side of said central chamber, a plurality ofpositioning members extending from the closed end, and a plurality ofapertures extending through the closed end; positioning said housing onsaid register circuit board by moving said positioning members intocontact with cooperating positioning members on said register circuitboard; positioning at least one light emitter in one of said pockets,and at least one light detector in at least one of said pockets on theother side of said central chamber with electrical leads extending fromsaid at least one light emitter and said at least one light detectortoward the close end of said pockets; moving said one or more lightemitters and light detectors into position within said pockets andthereby moving the electrical leads extending from said one or morelight emitters and said one or more light detectors through saidplurality of apertures to extend through said closed end beyond themolded housing into holes in said register circuit board; and connectingsaid electrical leads in circuit with said register circuit board. 2.The method of positioning and mounting a disk sensing optics assembly onthe register circuit board of an electric energy meter of claim 1wherein portions of said electrical leads are larger in cross sectionthan said apertures extending through the closed end of said housing,and inserting said electrical leads into said apertures by forcing saidelectrical leads into and through said apertures to extend through saidapertures and retain said one or more light emitters and detectors inplace in said pockets.
 3. The method of positioning and mounting a disksensing optics assembly on the register circuit board of an electricenergy meter of claim 2 wherein said cross section of said electricalleads includes a plurality of surfaces at angles to each other and thecross section of said apertures are substantially circular, and saidforcing said electrical leads into said apertures is with sufficientforce to cause the angular portions to cut into the housing surroundingsaid apertures thereby gripping said electrical leads and retaining saidone or more light emitters and detectors in place in said pockets. 4.The method of positioning and mounting a disk sensing optics assembly onthe register circuit board of an electric energy meter of claim 3wherein some of said positioning members extending from the closed endof said housing include spacers which contact said register circuitboard when said disk sensing optics assembly is moved into position onsaid register circuit board, stopping the movement and positioning thedisk sensing optics assembly in a predetermined position such that saidelectrical conductors extend into said holes in said register circuitboard a predetermined amount which is suitable for soldering the ends ofsaid electrical leads to the remote side of said register circuit board.5. The method of positioning and mounting a disk sensing optics assemblyon the register circuit board of an electric energy meter of claim 4wherein said electrical leads are inserted through holes in saidregister circuit board and are soldered in circuit with circuitry on theside of said register circuit board remote from said housing.
 6. Themethod of positioning and mounting a disk sensing optics assembly on theregister circuit board of an electric energy meter of claim 1 whereinthe electric energy meter includes a viewing end on one side of saidregister, and including the additional step of mounting said registercircuit board within said electric energy meter with the open end ofsaid central chamber facing away from the viewing end of said electricenergy meter with said register circuit board positioned between saidviewing end and said central chamber to shield the open end of saidcentral chamber from ambient light at said viewing end.
 7. The method ofpositioning and mounting a disk sensing optics assembly on the registercircuit board of an electric energy meter of claim 6 wherein saidregister circuit board is positioned and mounted with the side of saidregister circuit board remote from said housing facing toward saidviewing end of said electric energy meter.
 8. The method of positioningand mounting a disk sensing optics assembly on the register circuitboard of an electric energy meter of claim 7 including the additionalstep of mounting a rotatable optical shutter with a circumferentialcastellated portion rotatable within said central chamber and betweensaid one or more light emitters and light detectors, such that rotationof said shutter interrupts the light beams passing between said one ormore light emitters and light detectors.
 9. The method of positioningand mounting a disk sensing optics assembly on the register circuitboard of an electric energy meter of claim 8 including the additionalstep of rotating said castellated shutter in response to the electricalenergy being measured by said electric energy meter.
 10. The method ofpositioning and mounting a disk sensing optics assembly on the registercircuit board of an electric energy meter of claim 8 wherein said atleast one light emitter comprises two light emitters, and said at leastone light detector comprise two light detectors, the light emitters andlight detectors being positioned in pairs on opposite sides of saidcentral chamber, and rotating the castellations of said shuttersequentially past said pairs of light emitters and light detectors toprovide signals responsive to the direction of rotation of said shutterbased on the sequence in which the light beams between the multiplepairs of light emitters and light detectors are interrupted.
 11. Themethod of positioning and mounting a disk sensing optics assembly on theregister circuit board of an electric energy meter of claim 30 whereinsaid plurality of positioning members extending from the closed end ofsaid housing includes a plurality of posts through which said aperturesfor said electrical leads extend, and forcing said electrical leadsthrough said apertures in said posts.
 12. The method of positioning andmounting a disk sensing optics assembly on the register circuit board ofan electric energy meter of claim 11 wherein said housing includes lightopenings in said pockets adjacent said central chamber and positioningsaid pairs of light emitters and detectors within said pockets such thatthe light beams therebetween pass through said openings.
 13. A method ofpositioning and mounting a disk sensing optics assembly on the registercircuit board of an electronic register in an electric energy metercomprising the steps of:molding a housing including a central chamberopen at one end, with one or more pockets positioned on either side ofsaid central chamber, and a plurality of positioning members and aplurality of apertures extending through the closed end; inserting atleast one light emitter in one of said pockets and at least one lightdetector in at least one of said pockets on the other side of saidcentral chamber with electrical leads extending from said at least onelight emitter and at least one light detector toward the closed end ofsaid pockets; moving the one or more light emitters and detectors intoposition within said pockets and thereby moving the electrical leadsextending from the one or more light emitters and detectors through saidapertures in said closed end to extend beyond the molded housing;positioning said housing on said register circuit board by moving saidpositioning members into contact with cooperating positioning members onsaid register circuit board and moving said electrical leads into holesin said register circuit board; and connecting said electrical leads incircuit with said register circuit board
 14. The method of positioningand mounting a disk sensing optics assembly on the register circuitboard of an electric energy meter of claim 13 wherein said closed end ofsaid one or more pockets include a tapered opening tapering toward eachof said apertures, and the inserting of said at least one light emitterand at least one light detector moving said electrical leads throughsaid tapered shaped openings, which tapered openings guide the movementand positioning of said electrical leads into said apertures.
 15. Themethod of positioning and mounting a disk sensing optics assembly on theregister circuit board of an electric energy meter of claim 14 whereinsaid tapered openings are funnel shaped openings which guide themovement and positioning of said electrical leads.
 16. The method ofpositioning and mounting a disk sensing optic assembly on the registercircuit board of an electric energy meter of claim 13 wherein portionsof said electrical leads are larger in cross section than said aperturesin said housing, and inserting said electrical leads into said aperturesby forcing said electrical leads into and through said apertures toextend through said apertures and retain said one or more light emittersand detectors in place in said pockets.
 17. The method of positioningand mounting a disk sensing optics assembly on the register circuitboard of an electric energy meter of claim 16 wherein said cross sectionof said electrical leads includes a plurality of surfaces at angles toeach other and the cross section of said apertures are substantiallycircular, and said forcing said electrical leads into said apertures iswith sufficient force to cause the angular portions to cut into thehousing surrounding said apertures thereby gripping said electricalleads and retaining said one or more light emitters and detector inplace in said pockets.
 18. The method of positioning and mounting a disksensing optics assembly on the register circuit board of an electricenergy meter of claim 17 wherein some of said positioning membersinclude spacers which contact said register circuit board when said disksensing optics assembly is moved into position on said register circuitboard, stopping the movement and positioning the disk sensing opticsassembly in a predetermined position with said electrical conductorsextending into said holes in said register circuit board a predeterminedamount which is suitable for soldering to the remote side of saidregister circuit board without the necessity of trimming the electricalleads.
 19. The method of positioning and mounting a disk sensing opticsassembly on the register circuit board of an electric energy meter ofclaim 18 wherein said electrical leads which are inserted through holesin said register circuit board are soldered in circuit with circuitry onthe side of said register circuit board remote from said housing. 20.The method of positioning and mounting a disk sensing optics assembly onthe register circuit board of an electric energy meter of claim 13wherein the electric energy meter includes a viewing end on one side ofthe register including the additional step of mounting said registercircuit board within said electric energy meter with the open end ofsaid central chamber facing away from the viewing end of said electricenergy meter with said register circuit board between said viewing endand said central chamber to shield the open end of said central chamberfrom ambient light at said viewing end.
 21. The method of positioningand mounting a disk sensing optics assembly on the register circuitboard of an electric energy meter of claim 20 wherein said registercircuit board is positioned and mounted with the side of said registercircuit board remote from said housing facing toward said viewing end ofsaid electric energy meter.
 22. The method of positioning and mounting adisk sensing optics assembly on the register circuit board of anelectric energy meter of claim 41 including the additional step ofmounting a rotatable optical shutter with a circumferential castellatedportion rotatable within said central chamber and between said one ormore light emitters and light detectors, such that rotation of saidshutter interrupts the light beams passing between said one or morelight emitters and light detectors.
 23. The method of positioning andmounting a disk sensing optics assembly on the register circuit board ofan electric energy meter of claim 22 including the additional step ofrotating said castellated shutter in response to the electrical energybeing measured by said electric energy meter.
 24. The method ofpositioning and mounting a disk sensing optics assembly on the registercircuit board of an electric energy meter of claim 22 wherein said atleast one light emitter comprises two light emitters, and said at leastone light detector comprises two light detectors, the light emitters andlight detectors being positioned in pairs on opposite sides of saidcentral chamber, and rotating the castellations of said shuttersequentially past said pairs of light emitters and light detectors toprovide signals responsive to the direction of rotation of said shutterbased on the sequence in which the light beams between the multiplepairs of light emitters and light detectors are interrupted.
 25. Themethod of positioning and mounting a disk sensing optics assembly on theregister circuit board of an electric energy meter of claim 24 whereinsaid plurality of positioning members extending from the closed end ofsaid housing includes a plurality of posts through which said aperturesfor said electrical leads extend, and forcing said electrical leadsthrough the apertures in said posts.
 26. The method of positioning andmounting a disk sensing optics assembly on the register circuit board ofan electric energy meter of claim 25 wherein said housing includes lightopenings in said pockets adjacent said central chamber and positioningsaid pairs of light emitters and detectors within said pockets such thatthe light beams therebetween pass through said openings.